574 PRINCIPLES OF STRATIGRAPHY 



forming on the shores of Great Salt Lake in L^tah, where oolites are 

 constantly developing through the activities of unicellular algae. 

 Eolian limestones in which the grains are Foraminifera and par- 

 ticles of shells may also be deposited by the wind many miles in- 

 land and often high above the level of the sea. These deposits are 

 stratified and cross-bedded and probably more common than gen- 

 erally assumed, since they are usually taken for marine deposits. 

 The absence of marine organic remains larger than those trans- 

 portable by wind, however, indicates their eolian origin, while the 

 presence of land animals is an additional piece of evidence. Lime- 

 stones of this type have been described from the coast of the 

 Arabian Sea (Evans-14: 57^-5^0), where they constitute the Mifio- 

 litic formation, so called on account of the abundance of the for- 

 aminifer Miliola. The Junagarh limestone overlying the Deccan 

 trap in the Kathiawar Peninsula of western India is a typical ex- 

 ample of this kind of rock. It underlies the city from which it 

 takes its name, at a distance of about 30 miles from the sea, and 

 has a thickness probably exceeding 200 feet. It is mainly formed 

 of calcareous particles derived from shallow-water organisms of re- 

 cent types, each particle being ordinarily surrounded by an en- 

 velope of deposited carbonate of lime, the whole being bound to- 

 gether by a later cement of the same material. Interspersed with 

 the calcareous grains are minute mineral fragments derived from 

 the igneous rocks of the neighborhood, but they constitute only 

 from 6.5 to 12.5 per cent, of the whole. The limestone is divided 

 by horizontal planes into tiers 3 to 4 feet thick, the division planes 

 marking decided breaks in deposition. Between the planes the 

 lamination is very oblique and cut oflf abruptly, both above and be- 

 low, by the major division planes. Usually the inclination is differ- 

 ent on either side of the plane, the direction, which is generally to 

 the east, remaining constant, or varying even to reversal. The 

 angle of inclination with the horizontal may be anything up to 30°, 

 and may vary from point to point of the same division of the rock, 

 though on the whole it is rather regular. 



In other parts of the Kathiawar Peninsula similar conditions ex- 

 ist, and it has been found that the rock is purer in proportion to 

 its distance from the sea, along the border of which it is not infre- 

 quently mixed with much siliceous sand. (Fedden-15.) Some- 

 times, as on the south coast of the peninsula, the beds are rubbly 

 and earthy, and in them have been found two specimens of Bulimus, 

 two of Helix and one of Cyclotus. On the coast, at Verawal, the 

 Miliolite limestone passes laterally into an open, porous, sandy rock, 

 made up very largely of organic fragments and minute organisms. 



